3D printing is fast becoming a viable production tool for manufacturers across a diverse range of industries. But not all additive manufacturing technologies are equal in their industrial usefulness: metal additive processes like selective laser melting (SLM) are already widely used for end-use parts, but what of other processes like fused deposition modeling (FDM) or, in this particular case, selective laser sintering (SLS)?

Aerosint, an SLS specialist based in Belgium, is on a quest to develop the most factory-ready SLS printer on the market, and to this end has developed a machine that can offer selective, highly detailed deposition of multiple powder materials. The company says this is the first (and as of now only) multi-powder printing process that can print parts made of different materials by melting powder layers composed of more than one powder.

It works using a new multi-powder dispensing technology, with a dispenser composed of multiple patterning drums (one per powder type) that selectively deposit fine powder voxels line by line. This process produces a sintering-ready powder layer composed of more than one base material, and can pattern at rates of up to 200 mm/s—comparable to today’s SLS recoater travel speeds and more than ten times faster than the upper limit of a theoretical pipette array.

Excitingly, Aerosint says the 3D printing process is as “material-agnostic” as possible, which means a broad range of polymers, ceramics, and even metals with less-than-optimal powder size distribution and flowability characteristics can be used.

Yet there are bigger advantages to the new Aerosint technology than just combining multiple powders in a single 3D printing process. Besides this useful feature, the technology also produces virtually zero waste: by using an inert support powder, users can eliminate powder degradation that usually occurs when using the same polymer as both object and support material. Consequently, because no degradation of the support powder takes place, all of it can be reused in the next print job.

This is essentially what makes the Aerosint technology so unique. Other major powder additive manufacturing systems leave, on average, 80 to 90 per cent of powder unprocessed after a print, and recycling that unused powder has until now been near-impossible. This is because polymers exposed to high heat for long periods of time undergo chemical changes, making them mechanically unpredictable and therefore unusable as sintering materials.

And where other companies are attempting to tackle this problem by developing new powders that are more degradation-resistant, Aerosint’s solution is actually simpler: just make a process that can use two materials, one as the build material and one as the support material. In this way, a low-cost support material can be used in order to reduce wastage of the build material.

The effective re-use of powder enabled by this approach reduces powder consumption cost by 30 to 85 per cent compared to traditional laser sintering, and therefore makes it easier for users to experiment with expensive high-temperature polymers like PEEK. Aerosint believes this will make the SLS 3D printing technology a more viable option for the factory floor, since even a high turnover of parts will result in relatively low material expenditure.

Aerosint is currently awaiting a patent for its multi-powder SLS 3D printing technology, and expects it to transform industrial 3D printing.